Absorption, distribution, metabolism and elimination were begun on three ionic liquids that are promoted as replacements for halogenated solvents in degreasing applications. Oral and dermal studies are being conducted in support of the NTP sub-chronic toxicity studies. TBBPA and TBBPA-DBPE are used as flame retardents in circuit boards and polycarbonate-acrylonitrile-butadiene-styrene plastics. There is widespread worker exposure to these chemicals and possible consumer exposure. Special emphasis is being made to determine if TBBPA-DBPE is metabolized to produce 2,3-dibromopropyl ether, a known animal carcinogen. Present studies also include bioavailability studies of ionic liquids by the oral and dermal routes. Keywords Metabolite identification;NMR;HPLC;Mass spectrometry;Absorption;Distribution;Elimination;Kinetics;LSC;In vivo;In vitro;Radiolabeled compounds;Dermal;Gavage;IV;Inhalation;Mass balance;Ionic liquids;tetrabromobisphenol A;tetrabromobisphenol A-2,3 dibromopropyl ether;ionic liquids